1. Field of the Invention
The present invention pertains to chucks for use in gripping and turning a work-piece, and particularly to low-cost keyless chucks for operation in both the forward and reverse direction of rotation.
2. Description of the Prior Art
Keyless chucks are known which can be operated in both the forward and reverse rotation directions, such as would be required in applications calling for the ability to both drive and extract screws, for instance. However, such prior art typically are fabricated from parts which require comparatively expensive machining operations which effectively prevent use in those tools and applicances where high volume and low price are major factors dictating commercial success.
Also, the need to prevent corrosion in the machined moving parts of the prior art chucks, particularly between the workpiece-gripping jaws and the guides for the jaws, often has necessitated corrosion inhibiting materials to be applied in a separate operation after the final machining operations. Machining parts directly from corrosion resistant materials such as stainless steel can be difficult and relatively expensive, depending upon the amount of machining required and the scrap produced.